The present invention relates to simulators and in particular to arrangements for simulating the stress applied to a barrel by a projectile and by gun gas.
It is desirable to simulate the stress caused by the firing of a projectile through a barrel in order to measure the resulting strain. In addition, it is desirable to repeatedly simulate such stress so that barrel fatigue can be assessed. There are two general causes of stress during the firing of a projectile. Firstly, there is the stress caused by the gun gas. Secondly, there is the stress caused by the obturator of the projectile. This obturator, being larger than the bore of the barrel, is designed to deformably engage the rifling of a barrel.
The disadvantages surrounding firing an actual projectile merely for test purposes is evident. The projectile must either be fired into a large restraining target or into a large firing range. For repeated firings the cost can be exceedingly high. Merely pressurizing the barrel does not accurately simulate the stresses occurring during firing since this provides uniform stress as opposed to the non-uniform stress that actually occurs.
The present invention provides a simple and effective method for simulating the complex stresses caused by the firing of a projectile. A simple stress test is provided by employing a piston having an expansible periphery. The periphery of this piston is expanded and the barrel is pressurized between its breech and the piston to simulate the complex stresses produced by the firing of a projectile.